Connecting clusters of scentific research

The dominant scientific research surrounding Golden Rice focuses on engineering the pro vitamin A biosynthetic pathway into the rice endosperm. This concept, developed from this central research document found through, is what relates many areas of research to one another. Whilst the scientific debate as to whether or not Golden Rice contains vitamin A is relativity undisputed, we have seen a controversy among the scientific community  regarding the volume vitamin A in each rice grain. By using you are able to digitally map where researchers site one another and how they use this research to back up their own work. From this digital map provided below, you can see how scientific research is clustered together to cite one another ultimately trying to sever links that opponents are creating against their research. Below are a few of the clusters surrounding the central research document:

Cluster 1: The Makings of 'Golden Rice 2'
Scientists within this cluster are developing research directly related to Golden Rice. They have discovered a new way of engineering a pro vitamin A biosynthetic pathway that would increase the volume of vitamin A in the rice endosperm. By using the daffodil gene encoding photogene synthesis (psy), one of two genes used to develop Golden Rice, they found that it was limiting beta-carotene accumulation within the rice endosperm. After a series of cloning, over-expression, rice transformations, and cultivation analysis, they believe that by combining the psy with Erwinia uredovora carotene desaturase (crtl) you can increase the total carotenoids by up to 23 fold. The articles produced in this cluster directly cite Ye, X. et al (2000)(1) as a reference to the original process through which Golden Rice was engineered. It is used as a way to connect Golden Rice 2 with Golden Rice 1(2), and as a way to cut the link between Golden Rice and its inefficient reputation. This cluster was heavily documented by Syngenta researchers and the funds they provide towards the Golden Rice Project along with the World Bank and FAO. All of these actors have their own interests in the developed of Golden Rice.

Cluster 2: Other Genetically Modified Crops
A second major cluster of research surrounds the modification of other crops. Researchers concentrating on maize (3) and tomatoes (4) have all drawn on Ye, all (2000) as a source to back up their hypothesis that other foods can be enhanced with vitamin A. In Romer et al (2000) they believe that by genetically engineering a tomato in a similar way to the rice grain, you can increase the beta-carotene content by threefolds, this is a 45% increase in vitamin A. It directly cites Ye, X. et al (2000) as an example of a case study where this phenotype has been proven successful. Similarly, in the case of maize Aluru et al (2008), the article utilizes the success of the Golden Rice to illustrate how adopting the same methods of cloning, over-expression, transformation, and cultivate analysis you can increase the amount of vitamin A in other staple food sources. Here we find a cluster of new research using the established Golden Rice research to increase the scope of its technology.

Cluster 3: Detailed Analysis of why methods are legitimate
A third major cluster, evident from the cite space map, was concerned with the methods that key documents used to provide evidence for their research. Ye, X. et al (2000) has cited a number of these articles to prove their methods are sound. On particular article in this cluster contained information on carotenoid biosynthesis in flowering plants (5), seed-specific over-expression and how it increases the caroteniod yield (6), as well as information on the cultivation effects and the land management of GM crops on contrasting soil types (7). The methods they use are beyond my understanding or importance for this research topic, however they are key articles that researchers cite to strengthen the link between their research and reality. They prevent the opponent from unraveling their research without further investigation. Interestingly most of their research has nothing to do with GM crops at all. GM researchers have interpreted and applied their findings to back their claims, regardless as to whether these method documents were meant to be used for GM crops.
Here is the cite space cluster map showing the interconnected web of researchers work, as you can see the Ye, X et al (2000) article is the large pink ring and each color represents a particular cluster or research, each one having a link to this key article:
(1) Ye, X, et al., 2001. Engineering the provitamin A biosynthetic pathway into rice endosperm, science, Vol 287 (5451): 303
(2) Paine, J. A., 2001. Improving the nutritional value of Golden Rice through increased pro-vitamin A content, Nature Biotechnology: 
(3) Aluru, M., 2008. Generation of transgenic maize with enhanced provitamin A content, Journal of Experimental Botany, vol 59 (13): 3551-3562
(4) Romer, S. et al., 2000. Elevation of the provitamin A content of transgenic tomato plants, school of biological science, research articles, Natural America Inc: 
(5)Hirschberg, J., 2001. Carotenoid biosynthesis in flowering plants, plant biology, Vol 4 (3): 210-218 
(6) Shewmaker, CW. et al., 1999. Seed-specific overexpression of phytoene synthase: increase in carotenoids and other metabolic effects, plant journal, Vol 20 (4): 401-412. 
(7)Dobbermann, A., 2002. Site-specific nutrient management for intensive rice cropping systems in Asia, field crops research, Vol 74 (1): 37-66.